`timescale 1ns/1ns

module DFF_tb ();
    
    reg clk,D;
    wire Q;
    
    DFF DFF_tb(
    .clk(clk),
    .D(D),
    .Q(Q)
    );
    
    initial begin
        clk = 0;
        D   = 0;
        forever begin
            #60 D <= 1;//人为生成毛刺
            #22 D <= 0;
            #2  D <= 1;
            #2  D <= 0;
            #16 D <= 0;//维持16ns的低电平，然后让它做周期性的循环
        end
    end

    always #10 clk = ~clk;
    
endmodule
